Recovering oil from undersea wells often involves the use of flexible pipes to connect a well on a sea floor to production equipment at the surface. Such pipes must be able to withstand enormous pressures arising from the weight of water at extreme depths and thus include strong internal structures that prevent water pressure from collapsing the pipes.
Suitable internal pipe structures are traditionally provided through the use of steel carcasses within the pipes. A conventional steel carcass is a continuous hoop made by forming steel strips into an interlocked structure that can flex, withstand external pressure, and withstand axial forces. For example, short steel hoop segments may be formed and longitudinally crimped together to form an extended tubular structure. Accordion-like portions within each segment allow bending of the overall carcass. The carcass is typically covered with a thermoplastic liner which acts as a barrier to fluid. In addition, typical pipe designs include many external layers. The carcass prevents collapse of the thermoplastic liner and external layers. Fluids, such as oil, are transmitted through the pipe inside the carcass.